Converting arguments to an array

JavaScript performance comparison

Revision 6 of this test case created

Preparation code

<script>
  function arrayProtoSlice() {
      return Array.prototype.slice.apply(arguments);
  }

  function arrayLiteralSlice() {
      return [].slice.apply(arguments);
  }

  var slice = [].slice;
  function closure() {
    return slice.call(arguments);
  }

  function splice() {
      return [].splice.call(arguments, 0);
  }
  function push() {
      var x = [];
      x.push.apply(x, arguments);
      return x;
  }
  function unshift() {
      var x = [];
      x.unshift.apply(x, arguments);
      return x;
  }
  function whileDec() {
      var arr = [],
      i = arguments.length;
      while(i--) {
          arr[i] = arguments[i];
      }
      return arr;
  }

  var bigArray = new Array(1001).join("a").split("");
  var smallArray = new Array(6).join("a").split("");
 
  unshift.apply(null, bigArray).length === bigArray.length || alert('unshift broken');
  push.apply(null, bigArray).length === bigArray.length || alert('push broken');
  splice.apply(null, bigArray).length === bigArray.length || alert('splice broken');
  arrayProtoSlice.apply(null, bigArray).length === bigArray.length || alert('arrayProtoSlice broken');
  arrayLiteralSlice.apply(null, bigArray).length === bigArray.length || alert('arrayLiteralSlice broken');
whileDec.apply(null, bigArray).length === bigArray.length || alert('arrayLiteralSlice broken');
</script>

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Testing in unknown unknown
Test Ops/sec
Array prototype slice
arrayProtoSlice.apply(null, bigArray);
arrayProtoSlice.apply(null, smallArray);
pending…
Array literal slice
arrayLiteralSlice.apply(null, bigArray);
arrayLiteralSlice.apply(null, smallArray);
pending…
Array push
push.apply(null, bigArray);
push.apply(null, smallArray);
pending…
Array splice
splice.apply(null, bigArray);
splice.apply(null, smallArray);
pending…
Unshift
unshift.apply(null, bigArray);
unshift.apply(null, smallArray);
pending…
Closure
closure.apply(null, bigArray);
closure.apply(null, smallArray);
pending…
While loop
whileDec.apply(null, bigArray);
whileDec.apply(null, smallArray);
pending…

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